export default {
	namespaced:true,
	
	state:()=>({//购物车的数组
		cart:JSON.parse(uni.getStorageSync('cart') || '[]')
	}),
	
	mutations:{
		addToCart(state,goods){//加入购物车的方法
			const findResult= state.cart.find(x=>x.goods_id === goods.goods_id)
			
			if(!findResult) {
				state.cart.push(goods)
			}else{
				findResult.goods_count++
			}
			this.commit('m_cart/saveToStorage')
		},
		saveToStorage(state){
			uni.setStorageSync('cart',JSON.stringify(state.cart))
		},
		//更新购物车中商品的勾选状态
		updateGoodsState(state,goods){
			const findResult =state.cart.find(x=> x.goods_id === goods.goods_id)
			if(findResult){
				findResult.goods_state=goods.goods_state
				//修改勾选状态并保存在持久存储中
				this.commit('m_cart/saveToStorage')
			}
		},
		// 更新购物车中商品的数量
		updateGoodsCount(state,goods){
			const findResult= state.cart.find(x=> x.goods_id===goods.goods_id)
			if(findResult){
				findResult.goods_count=goods.goods_count
				
				//修改商品数量并保存在持久存储中
				this.commit('m_cart/saveToStorage')
			}
		},
		removeGoodsById(state,goods_id){//根据id删除对应的商品
			state.cart = state.cart.filter(x=> x.goods_id !== goods_id)
			//删除商品并保存在持久存储中
			this.commit('m_cart/saveToStorage')
		},
		updateAllGoodsState(state,newState){//更新全部商品的勾选状态
			state.cart.forEach(x=> x.goods_state=newState)
			
			this.commit('m_cart/saveToStorage')
		}
	},
	
	getters:{
		total(state){//购物车中所有的总数量
			// let c =0 forEach方法实现
			// state.cart.forEach(x=>c +=x.goods_count)
			// return c
			//数组reduce方法实现
			return state.cart.reduce((total,item)=>total += item.goods_count,0)
		},
		checkedCount(state){//勾选商品的总数量
			return state.cart.filter(x=>x.goods_state).reduce((total,item)=>total+=item.goods_count,0)
		},
		checkedGoodsAmount(state){//勾选商品的总价
		 	return state.cart.filter(x=>x.goods_state).reduce((total,item)=>total+=item.goods_count*item.goods_price,0).toFixed(2)
		}
	}
}